Metropolitan Police officers on duty near parliament have been “briefed to intervene appropriately where they hear or see breaches of the law” after Anna Soubry accused them of ignoring abuse hurled at politicians and journalists.

The Tory MP was called a “Nazi” by chanting protesters and speaking to Good Morning Britain on Tuesday, the she said there was a small group of people “roaming around Westminster intimidating people going about their lawful business”.

The pro-EU Broxtowe MP added that while she expected a level of criticism and abuse as an MP, she expected authorities to act when it “crossed the line”.

She told GMB: “It crossed the line in December, it was journalists who were being attacked.

“(Sky News’ political editor) Faisal Islam, who is male, was racially abused by these people, it’s the same group, all on video and the policy of the Metropolitan Police is to ignore it.”

In a statement on the policing operation at the Westminster Brexit protests, Deputy Assistant Commissioner Laurence Taylor, for Met Operations, said: “Police continue to assess if any crimes have been committed following a third party report of a public order offence on Monday, 7 January, in the area of College Green.

“If a crime has been committed the matter will be fully investigated.

“There has been no arrest at this stage.”

On Monday evening it emerged a cross-party group of 50 MPs had written to Scotland Yard asking for greater protection outside parliament after the abuse Soubry received.

Police are investigating whether any criminal offence was committed when Soubry was verbally attacked while doing live interviews on College Green on Monday.

The Tory MP was discussing Theresa May’s Brexit plan with presenter Simon McCoy when they had to stop their conversation due to chants from a group of people just out of view of the camera.

Pointing to the protesters, Soubry said: “I do object to being called a Nazi, actually. I think this is astonishing. This is what has happened to our country, this is what’s happened to our country.

“But anyway, let’s try and stay positive about things.”

The protesters, who were out of shot, then began chanting: “Liar, liar, liar”.

Asked whether MPs should be offered greater protection while the “meaningful vote” on Brexit is debated over the next few days, the PM’s spokesman said: “There are existing laws in relation to public order, harassment and making threats.

“Where laws are already in place, it’s important that they are respected.”

The Labour MP for Sheffield Heeley, Louise Haigh, told the BBC on Tuesday that despite having a panic alarm and extra security installed in her home after previous threats, she still does not feel safe in her home.

She said: “A couple of years since the murder of Jo Cox has meant that very few of us feel like we work in a safe working environment.”

A spokesman for the Metropolitan Police said: “Police received a third-party report of a public order offence on Monday, 7 January, in the area of College Green, SW1.

“Officers are assessing if any crimes have been committed. There has been no arrest at this stage.”